Roll joint steering

ABSTRACT

A vehicular steering arrangement is provided which is substantially unaffected and uncontaminated by a rolling relationship between separate chassis portions of the vehicle. Steering gear on one chassis portion provides accurate mechanical steering on a separate and relatively rotatable chassis portion without passing any portion of the steering connecting apparatus through the roll axis between the two chassis portions. The steering apparatus between the two chassis portions has a compact freely rotatable interconnection effectively concentric with the roll axis. Steering motion is provided by the translation of this rotatable interconnection transverse the roll axis. A continuous passageway is provided therethrough to allow an interchassis drive shaft to pass directly along the inter-chassis roll axis inside the rotatable interconnection.

Unite States Patent [1 1 Cross July 17,1973

[ ROLL JOINT STEERING [75] Inventor: John W. Cross, San Jose, Calif.

[73] Assignee: Lockhead Aircraft Corporation,

Burbank, Calif.

22 Filed: Aug.25, 1971 21 Appl. No; 174,853

Primary ExaminerKenneth H. Betts Atl0rney- Paul F. Morgan and George C.Sullivan [57] ABSTRACT A vehicular steering arrangement is providedwhich is substantially unaffected and uncontaminated by a rollingrelationship between separate chassis portions of the vehicle. Steeringgear on one chassis portion provides accurate mechanical steering on aseparate and relatively rotatable chassis portion without passing anyportion of the steering connecting apparatus through the roll axisbetween the two chassis portions. The steering apparatus between the twochassis portions has a compact freely rotatable interconnectioneffectively concentric with the roll axis. Steering motion is providedby the translation of this rotatable interconnec tion transverse theroll axis. A continuous passageway is provided therethrough to allow aninterchassis drive shaft to pass directly along the inter-chassis rollaxis inside the rotatable interconnection.

12 Claims, 5 Drawing Figures Patented July 17, 1973 3,746,119

3 Sheets-Sheet 1 JOHN w. CROSS v INVENTOR.

BY I Agent Attorney Patented July 17, 1973 3,746,l l9

3 Sheets-Sheet 2 JOHN w. CROSS INVENTOR.

0 :0 BY "Agent Patented July 17, 1-973 3,746,119

3 Sheets-Sheet :5

OHN W. CROSS INVENTOR.

ROLL JOINT STEERING The invention relates to an improved steeringarrangement and steering interconnection between rollably interconnectedchassis portions of a vehicle, which steering interconnectionsubstantially eliminates the effect of inter-vehicular roll on thevehicular steering. The invention provides a simple and compact steeringmechanism by which a driver on one section of a multisection vehicle maysteer the wheels (or other ground engagement means) on one or more ofthe other sections without relative roll between the sections causingundesirable wheel turning with consequent wheel scuffing or undesiredsteering actions.

This steering problem is recognized in the art. For example in U.S. Pat.No. 3,183,991 at Column 12 it is stated that the result of interchassisroll on the steering is the delivery of a spurious rotary input of thesteering mechanism which does not arise from, or correspond to, themotion of the steering wheel. Various attempted solutions to the problemin the prior art include those of the above-cited patent as well as thelongitudinal push-pull arrangements illustrated in U.S. Pat. Nos.3,002,301 and 3,471,116 (note Columns and 6 and FIGS. 14 and 16).However, these arrangements have various limitations and disadvantages,particularly where a compact design within space limitations isrequired. The present steering arrangement is particularly well suitedto incorporation as a compact part of a compact interchassis roll jointbetween closely adjacent chassis portions. It provides positivemechanical steering without requiring any hydraulic components.

Further objects, features and advantages of the invention pertain to theparticular arrangement and structure whereby the above mentioned aspectsof the invention are attained. The invention will be better understoodby reference to the following description and to the drawings forming apart thereof, wherein:

FIG. 1 is a partially schematicized perspective view of an exemplarysteering arrangement in accordance with the present invention on aschematicized portion of an exemplary two-section vehicle;

FIG. 2 is a front plan view transverse the vehicle roll axis of thesteering arrangement of FIG. 1 with neutral (straight ahead) steering;

FIG. 3 is a cross-sectional view taken along the vehicle roll axis,along the line'3--3 of FIG. 2;

FIG. 4 is the same view as FIG. 2 but showing the position of thesteering apparatus with neutral steering but interchassis roll of thevehicle; and

FIG. 5 is the same view as FIG. 2 but showing a positive steering inputto the steering apparatus.

Referring to the drawings, FIG. I 5, there is shown therein an exemplarysteering arrangement 10 in accordance with the present invention. Thesteering arrangement [0 is applicable to almost any type of vehicle withtwo or more pivotably interconnecting chassis portions. Accordingly,only a portion of an exemplary vehicle 12 sufficient to show thesteering arrangement 10 thereon is illustrated here. Referringparticularly to FIG. 1 and FIG. 3, it may be seen that the exemplaryvehicle 12 here comprises a first chassis portion 14 rotatably connectedto a second chassis portion 16 by an annular intermediate roll joint 18shown in FIG. 3. The roll joint 18 provides relative rotation betweenthe first and second chassis portions about an inter-chassis roll axis19.

By means of the steering arrangement 10 vehicle wheels 20 (or othersuitable ground engagement means) on the second chassis portion 16 maybe directly, mechanically and positively steered by steering gear 22 onthe first chassis portion 14 irrespective of the degree of roll betweenthe first and second chassis portions. The steering gear 22 may be anyconventional or suitable steering gear, and it will be appreciated thatit may be additionally connected to other vehicle wheels on the firstchassis portion 14 or other chassis portions. Only a single steeringinterconnection is illustrated here for clarity. It may be seen that thesteering arrangement 10 provides a large open passageway 24 between thefirst and second chassis portions, extending along and surrounding theinter-chassis roll axis 19, in which passageway 24 an inter-chassisdrive shaft 42 may be located.

Considering the main elements of the steering arrangement 10 in theirconnected sequence, it may be seen that steering motion by the operatorof the steering gear 22 is transmitted by a link 26 to rotate a lever28. The lever 28 is in turn connected to one end of a steering shaft 30,which is rotatably mounted about its own central axis 31 to the firstchassis portion 14. The steering shaft 30 and its axis of rotation 31extends into the second chassis portion 16 parallel to, butsubstantially spaced vertically above, the roll axis 19. The rotation ofthe steering shaft 30 about its axis 31 by the lever 28 providestransmission of the steering impulse through the roll joint 18 to thesecond chassis portion 16 and connects to an inner ring 32 mating withan outer ring 34. The outer ring 34 then connects with the wheelsteering means 38 on the second chassis portion The inner ring 32 issecured to the opposite end of the steering shaft 30 from the lever 28,i.e., in the second chassis portion 16. It may be seen that the innerring 32 here is a thin, large diameter hollow ring effectivelyconstituting a steering lever normally concentrically surrounding theroll axis 19, transverse thereto. The steering shaft 30 is fastened toone side of (eccentrically of) the inner ring 32. The inner ring extendsat right angles from the axis of rotation 31 of the'steering shaft 30,toward, but spaced from (around) the roll axis 19.

As may be seen from FIG. 5, rotation of the inner ring 32 by thesteering shaft 30 causes a lateral translation of the inner ring 32about the axis 31 relative to the roll axis 19. The outer ring 34rotatably closely surrounds the inner ring 32 and therefore istranslated therewith. This outer ring 34 constituting a rotatableconnector means is mounted to the second chassis portion 16 for suchsteering translational movement only. Its outer edge thus may beconnected to conventional connecting rods 36 at each side, whichconventionally impart steering movement to the vehicle wheels 20 throughconventional wheel steering means 38.

Considering in greater detail the inner ring 32 and the outer ring 34and their interconnection, itmay be seenthat they together provide arotational bearing and an uninterrupted passageway 24 along theinner-chassis roll axis 19. As shown in FIG. 3, they require littleadditional space since they are concentric with, closely spaced from,and parallel to, the roll joint 18. The inner ring 32 operates as ahollow steering lever or round eccentric carn acting about the axis ofrotation 31 of the steering shaft 30. A cylindrical bearing surface 40on the outer periphery of the inner ring or steering lever 32 mateswithin a correspondingly cylindrical bearing surface on the innerperiphery of the outer ring 34. The cylindrical bearing surface 40 hasits geometric center directly concentric the roll axis 19 when thesteering gear 22 is in its neutral position. Thus, as illustrated inFIG. 4, the inner ring 32 and outer ring 34 are freely relativelyrotatable with respect to one another about the roll axis 19. When onechassis portion rolls relative to the other, the inner ring 32 simplyfreely concentrically rotates within the outer ring 34 without impartingany translational movement thereto and therefore without imparting anysteering movement to the vehicle wheels 20.

Considering now the situation where a steering movement is impartedthrough the steering gear 22 for turning the vehicular wheels 20, it maybe seen from FIG. for example that, in addition to any roll rotationabout the roll axis 19, that the inner ring or steering lever 32 nowadditionally rotates about the axis of rotation 31 on the steering shaft30. This steering rotation does impart a movement to the outer ring 34because this rotation is not concentric with respect to the outer ring34. Thus for steering movements the inner ring 32 acts as aneccentrically mounted cam and the outer ring 34 acts as a cam followertranslated thereby. The extent of this translation is a function of thedegree of rotation of the steering shaft 30 and the effective lever armprovided by the spacing between the axis of rotation 31 and the rollaxis 19. Le, in steering the inner ring 32 acts as a lever extendingfrom the axis ofl,rotation 31 down toward, and effectively geometricallyacting at, the roll axis 19 but without actually physically occupyingthe space adjacent the roll axis 19.

A principal advantage, in addition to the extreme compactness of thesteering arrangement 10, is the useable space provided directly at andadjacent the roll axis 19 between the two chassis portions by thepassageway 24. This allows an interchassis drive shaft 42 to passthrough this passageway 24 along the exact roll axis 19, simplifying thedrive train arrangement. Additionally, innerchassis hydraulic lines 44and other interchassis connection may be conveniently provided betweenthe two chassis portions, without interference by interchassis roll, bypassing them through the enclosed, and therefore protected, passageway24 at or directly adjacent the roll axis 19. Where the drive shaft 42 isconcentric the roll axis 19 the hydraulic lines 44 may be simply spacedconveniently closely around the drive shaft 42 within the passageway 24as shown;

The outer ring'34 is pivotably mounted to a second chassis portion 16 soas to be moveable only in the desired steering translational movement.That is, the outer ring 34 is mounted so that it is free to move onlyalong a single generally linear axis transverse the roll axis 19,substantially along the lines of the connecting rods 36. This isaccomplished here by a parallelogram linkage relationship. A verticalarm 46 pivotably connects at its opposite ends between the secondchassis l6 and the outer periphery of the outer ring 34. It may be seenthat the arm 46 is parallel to, spaced from, and the same length as, theeffective lever arm of the inner ring 32 between its axis of rotation 31and the roll axis 19. Thus, a parallelogram linkage relationship isprovided which directs the movement of the outer ring 34 only along agenerally horizontal axis transverse the roll axis 19.

It may be seen that there has been described here an improved steeringarrangement and steering interconnection means for a vehicle having aplurality of interrotatable chassis portions. While the apparatusdescribed herein is presently considered to be preferred, it iscontemplated that other variations and modifications within the purviewof those skilled in the art can be made. The following claims areintended to cover all such variations and modifications as fall withinthe true spirit and scope of the invention.

What is claimed is:

1. ln a vehicle having at least first and second interconnecting chassisportions rotatable with respect to one another about an inter-chassisroll axis, and a steering arrangement wherein steering gear on saidfirst chassis portion of said vehicle is positively, mechanically,steeringly connected to vehicular steering means on said second chassisportion, the improvement in said steering arrangement of steeringinter-connection means between said first and second chassis portionscomprising:

rotational bearing means providing an uninterrupted passageway alongsaid inter-chassis roll axis between said first and second chassisportions,

said bearing means having first and second bearing elements both spacedfrom said inter-chassis roll axis,

said second bearing element being freely relatively rotatable withrespect to said first bearing element about an axis of rotation which isnormally concentric with said inter-chassis roll axis,

said first bearing element connecting with said steering gear and beingmounted for translation by said steering gear transversely of saidinter-chassis roll axis,

said second bearing element being rotatably mounted to said firstbearing element for corresponding translation by said first bearingelement transversely of said inter-chassis roll axis;

and connecting means connecting said second bearing element with saidvehicular steering means on said second chassis portion;

whereby said steering arrangement is substantially unaffected byinter-chassis rotation.

2. The steering arrangement of claim 1 wherein said first and secondbearing elements are rotatably mating concentric annular rings.

3. The steering arrangement of claim 1 wherein a inter-chassis vehiculardrive shaft with an axis of rotation extending along said inter-chassisroll axis passes through said rotational bearing means.

4. The steering arrangement of claim 1 wherein vehicular inter-chassiselectrical and hydraulic lines pass through said rotational bearingmeans adjacent said inter-chassis roll axis.

5. The steering arrangement of claim 1 wherein said second bearingelement is mounted to said second chassis portion by connecting meansproviding freedom of movement of said second bearing element only alonga generally linear axis transverse said inter chassis roll axis.

6. In a vehicle having at least first and second interconnecting chassisportions rotatable with respect to one another about an inter-chassisroll axis, and a steering arrangement wherein steering gear on saidfirst chassis portion of said vehicle is positively mechani callysteeringly connected to vehicular wheel steering means on said secondchassis portion, the improvement in said steering arrangementcomprising:

a steering shaft rotatably connected to said steering gear on said firstchassis portion,

said steering shaft having an axis of rotation parallel to and spacedfrom said inter-chassis roll axis,

said steering shaft extending from said first chassis portion to saidsecond chassis portion continuously spaced away from said inter-chassisroll axis;

a steering lever at said second chassis portion connected to and rotatedby said steering shaft,

said steering lever extending from said axis of rotation of saidsteering shaft toward but spaced from said inter-chassis roll axis,

said steering lever being connected to said vehicular wheel steeringmeans on said second chassis portion for steering movement of saidvehicular wheels;

and rotatable connector means rotatably interconnecting said steeringlever with said vehicular wheel steering means effectively geometricallyat said inter-chassis roll axis so that inter-chassis roll impartssubstantially no steering movement to said vehicular wheel steeringmeans,

said rotatable connecting means imparting steering movement to saidvehicular wheel steering means by rotation of said steering lever bysaid steering shaft about said axis of rotation of said steering shaft;

whereby said steering arrangement is substantially unaffected by saidinter-chassis rotation.

7. The steering arrangement of claim 6 wherein:

said steering lever is an annular hollow ring extending around andspaced from said inter-chassis roll axis,

said ring having a circular bearing surface with a geometric centernormally at said inter-chassis roll axis,

said ring being rotatable by said steering gear about said axis ofrotation of said steering shaft to provide eccentric rotation of saidbearing surface relative to said inter-chassis roll axis;

and wherein said rotatable connector means comprises a follower bearingon said second chassis portion spaced from said inter-chassis roll axisand engaging said bearing surface of said ring for translation of saidfollower bearing by said eccentric rotation of said bearing surface,

said rotatable connector means providing free rotation of said ringwithout translation of said follower bearing for concentric rotation ofsaid ring about said inter-chassis roll axis;

and wherein said follower bearing steeringly connects with saidvehicular wheel steering means on said second chassis.

8. The steering arrangement of claim 7 wherein said follower bearing ismounted to said second chassis portion by connecting means providingfreedom of movement of said follower bearing only along a generallylinear axis transverse said inter-chassis roll axis.

9. The steering arrangement of claim 7 wherein said ring and saidrotatable connector means provide a large uninterrupted open passagewayalong said inter-chassis roll axis between said first and second chassisportions.

10. The steering arrangement of claim 9 wherein a inter-chassisvehicular drive shaft with an axis of rotation concentric saidinter-chassis roll axis passes through said passageway.

11. The steering arrangement of claim 10 wherein vehicular inter-chassiselectrical and hydraulic lines pass through said passageway directlyadjacent said drive shaft.

12. The steering arrangement of claim 6 wherein a inter-chassisvehicular drive shaft with a central axis continuously directlyconcentric said intenchassis roll axis passes between said first andsecond chassis portions continuously spaced from said steeringarrangement.

1. In a vehicle having at least first and second interconnecting chassisportions rotatable with respect to one another about an inter-chassisroll axis, and a steering arrangement wherein steering gear on saidfirst chassis portion of said vehicle is positively, mechanically,steeringly connected to vehicular steering means on said second chassisportion, the improvement in said steering arrangement of steeringinter-connection means between said first and second chassis portionscomprising: rotational bearing means providing an uninterruptedpassageway along said inter-chassis roll axis between said first andsecond chassis portions, said bearing means having first and secondbearing elements both spaced from said inter-chassis roll axis, saidsecond bearing element being freely relatively rotatable with respect tosaid first bearing element about an axis of rotation which is normallyconcentric with said inter-chassis roll axis, said first bearing elementconnecting with said steering gear and being mounted for translation bysaid steering gear transversely of said inter-chassis roll axis, saidsecond bearing element being rotatably mounted to said first bearingelement for corresponding translation by said first bearing elementtransversely of said inter-chassis roll axis; and connecting meansconnecting said second bearing element with said vehicular steeringmeans on said second chassis portion; whereby said steering arrangementis substantially unaffected by inter-chassis rotation.
 2. The steeringarrangement of claim 1 wherein said first and second bearing elementsare rotatably mating concentric annular rings.
 3. The steeringarrangement of claim 1 wherein a inter-chassis vehicular drive shaftwith an axis of rotation extending along said inter-chassis roll axispasses through said rotational bearing means.
 4. The steeringarrangement of claim 1 wherein vehicular inter-chassis electrical andhydraulic lines pass through said rotational bearing means adjacent saidinter-chassis roll axis.
 5. The steering arrangement of claim 1 whereinsaid second bearing element is mounted to said second chassis portion byconnecting means providing freedom of movement of said second bearingelement only along a generally linear axis transverse said inter-chassisroll axis.
 6. In a vehicle having at least first and secondinterconnecting chassis portions rotatable with respect to one anotherabout an inter-chassis roll axis, and a steering arrangement whereinsteering gear on said first chassis portion of said vehicle ispositively mechanically steeringly connected to vehicular wheel steeringmeans on said second chassis portion, the improvement in said steeringarrangement comprising: a steering shaft rotatably connected to saidsteering gear on said first chassis portion, said steering shaft havingan axis of rotation parallel to and spaced from said inter-chassis rollaxis, said steering shaft extending from said first chassis portion tosaid second chassis portion continuously spaced away from saidinter-chassis roll axis; a steering lever at said second chassis portionconnected to and rotated by said steering shaft, said steering leverextending from said axis of rotation of said steering shaft toward butspaced from said inter-chassis roll axis, said steering lever beingconnected to said vehicular wheel steering means on said second chassisportion for steering movement of said vehicular wheels; and rotatablecOnnector means rotatably inter-connecting said steering lever with saidvehicular wheel steering means effectively geometrically at saidinter-chassis roll axis so that inter-chassis roll imparts substantiallyno steering movement to said vehicular wheel steering means, saidrotatable connecting means imparting steering movement to said vehicularwheel steering means by rotation of said steering lever by said steeringshaft about said axis of rotation of said steering shaft; whereby saidsteering arrangement is substantially unaffected by said inter-chassisrotation.
 7. The steering arrangement of claim 6 wherein: said steeringlever is an annular hollow ring extending around and spaced from saidinter-chassis roll axis, said ring having a circular bearing surfacewith a geometric center normally at said inter-chassis roll axis, saidring being rotatable by said steering gear about said axis of rotationof said steering shaft to provide eccentric rotation of said bearingsurface relative to said inter-chassis roll axis; and wherein saidrotatable connector means comprises a follower bearing on said secondchassis portion spaced from said inter-chassis roll axis and engagingsaid bearing surface of said ring for translation of said followerbearing by said eccentric rotation of said bearing surface, saidrotatable connector means providing free rotation of said ring withouttranslation of said follower bearing for concentric rotation of saidring about said inter-chassis roll axis; and wherein said followerbearing steeringly connects with said vehicular wheel steering means onsaid second chassis.
 8. The steering arrangement of claim 7 wherein saidfollower bearing is mounted to said second chassis portion by connectingmeans providing freedom of movement of said follower bearing only alonga generally linear axis transverse said inter-chassis roll axis.
 9. Thesteering arrangement of claim 7 wherein said ring and said rotatableconnector means provide a large uninterrupted open passageway along saidinter-chassis roll axis between said first and second chassis portions.10. The steering arrangement of claim 9 wherein a inter-chassisvehicular drive shaft with an axis of rotation concentric saidinter-chassis roll axis passes through said passageway.
 11. The steeringarrangement of claim 10 wherein vehicular inter-chassis electrical andhydraulic lines pass through said passageway directly adjacent saiddrive shaft.
 12. The steering arrangement of claim 6 wherein ainter-chassis vehicular drive shaft with a central axis continuouslydirectly concentric said inter-chassis roll axis passes between saidfirst and second chassis portions continuously spaced from said steeringarrangement.